On Mi, 2016-07-06 at 14:34 +0200, Linus Walleij wrote: > On Wed, Jul 6, 2016 at 12:27 PM, Johan Hovold <johan@xxxxxxxxxx> wrote: > > What's wrong with naming the pins in DT and use that for lookups? > > That works. It relies on the developers using sane naming conventions > though. (This problem is prevalent everywhere I guess, a human problem, > not a technical one.) I made this patch: > http://marc.info/?l=linux-arm-kernel&m=146672328215354&w=2 > > There is a standard document for these boards (96board) specifying > the names of the GPIO lines to be "GPIO-A" thru "GPIO-L". > > So a user can iterate across the gpiochips (as is done in lsgpio) > and pick the lines with the right names. This discussion caused me remember a concern regarding the chardev interface: Is it still be possible to give specific users/groups access to individual GPIOs? This is currently possible in the sysfs interface with chown/chmod. I don't see how per-GPIO permissions would translate to a per-gpiochip device. Am I overlooking some better way to give non-root users granular access to GPIOs? Or is that intentionally out of scope for the chardev interface? Yours, Jan -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
